Endoscopic surgical techniques are gaining wide acceptance among both surgeons and patients. There are many benefits associated with the use of endoscopic surgical techniques including reduced avenues for infection, reduced trauma, and a decrease in both the post-operative recuperative period and the duration of the hospital stay. Endoscopic is defined to include laparoscopic and arthroscopic.
Various types of endoscopic surgical instruments have been developed for use in these endoscopic surgical procedures, including ligating clip appliers. Conventional ligating clip appliers currently used in endoscopic procedures typically consist of a frame and a handle having an actuating trigger, an actuating mechanism, and a distal pair of jaws. The jaws typically consist of a pair of opposed jaw members which are angulated with respect to each other. The jaw members typically have inner grooves for retaining the legs of a ligating clip. The outer sides of the jaw members typically have cam surfaces; the jaws are typically closed or actuated by sliding a channel-like member over the cam surfaces thereby forcing the jaw members inward. Ligating clips are inserted between the jaws within the inner grooves, either by an automatic feed or by a single feed. When using a single feed, the jaws are typically inserted into a cartridge containing ligating clips thereby causing a ligating clip to be engaged by the jaws. A conventional ligating clip has a pair of outwardly extending legs connected at an apex. The legs typically extend in a v-shaped manner from the apex and then change direction angularly at a knee to extend outwardly parallel to the longitudinal axis of the clip.
When using a ligating clip applier in an endoscopic procedure, the instrument is initially inserted through a trocar cannula into a body cavity. It will be appreciated that the size of ligating clip is limited, in part, by the inner diameter of the trocar. The clip is then typically applied to a blood vessel or tissue by actuating the trigger which causes the actuating mechanism to engage the jaws, causing the jaws to squeeze the open ligating clip until it forms about the blood vessel or tissue. Typically, at least two clips are applied to a blood vessel or tissue along each side of an intended cut.
There are several deficiencies associated with conventional endoscopic ligating clip appliers currently used in endoscopic surgical procedures. One deficiency relates to the configuration of the jaws of the conventional clip applier. A clip formed by conventional jaws tends to have a relatively thick clip gap consisting of an apex gap and one or more gaps distal to the apex and proximal to the distal ends of the legs. This thick gap is undesirable. Depending upon the size and mechanical characteristics of the blood vessel clipped, it is possible for the blood vessel to move within the formed clip gap, thereby possibly allowing some blood flow through the clipped vessel. It is also possible that the clip may fall off of the blood vessel and into the body cavity.
Another disadvantage of conventional ligating clip appliers is that they typically do not have rearward clip retention. That is, the legs of a ligating clip are substantially retained by retention grooves in the jaws, however, the apex of the clip and the portions of the legs adjacent to the apex and proximal to the knees are not retained. Typically, as a clip is formed by displacing the jaws inwardly, the clip slides proximally in the grooves, since there is no rearward restraint acting upon the apex. If appropriate care is not taken during forming as the clip slides rearward, the vessel's position with respect to the clip may be changed. This can result in the misapplication of a formed clip.
The jaws of a ligating clip applier are typically used by the endoscopic surgeon to manipulate tissue or move blood vessels. This is done by simply engaging the blood vessel or tissue within the open jaws without actuating the jaws. Using a conventional ligating clip applier the surgeon has only 2.5 degrees of movement freedom. That is, the vessel or tissue may be manipulated by the open jaws up and down, left and right, and in. It would be desirable to have a ligating clip applier having jaws which would provide the surgeon with additional degrees of freedom for manipulating tissue.
Another deficiency associated with conventional ligating clip appliers is that it is often difficult for the endoscopic surgeon to control the position of the blood vessel within the jaws of a conventional ligating clip applier. Typically an endoscopic surgical procedure is performed using an endoscope which does not provide the surgeon with three dimensional depth of field. It is often difficult for the endoscopic surgeon to be absolutely certain that the blood vessel is within the jaws of the ligating clip applier prior to applying or forming a clip. If the blood vessel is not entirely within the jaws when the clip is applied, the blood vessel may be only partially contained by the clip and not fully ligated. In addition, the blood vessel may possibly not be within the jaws at all when the surgeon applies the ligating clip, resulting in the formed clip being released to the body cavity. Typically, the clip must then be retrieved from the patient's body cavity.
Yet another deficiency associated with conventional ligating clip appliers is that the size of a clip is limited, in part, by the internal diameter of a trocar through which the ligating clip applier is inserted. This is due, in part, to the configuration of the jaws of a conventional ligating clip applier wherein the clip is retained by the jaws with the outwardly extending jaws substantially in alignment with the longitudinal axis of the clip applier. Therefore, the overall width of the clip is a limiting factor with regard to insertion through a trocar.
What is needed in this field is a ligating clip applier which overcomes these deficiencies and which is easy to use by the endoscopic surgeon and economical to manufacture.